/*
 * Copyright (c) 2016, WSO2 Inc. (http://wso2.com) All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.wso2.msf4j.internal.mime;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import java.io.IOException;
import java.io.InputStream;
import java.util.Properties;

/**
 * This class lazily loads the mime-map.properties file
 * and maps file extension to mime type using the file.
 */
public class MimeMapper {

    private static Properties mimeMap = null;
    private static final Logger log = LoggerFactory.getLogger(MimeMapper.class);

    private static void loadMimeMap() throws IOException {
        mimeMap = new Properties();
        InputStream inputStream = MimeMapper.class.getClassLoader()
                .getResourceAsStream("mime-map.properties");
        if (inputStream != null) {
            mimeMap.load(inputStream);
            try {
                inputStream.close();
            } catch (IOException e) {
                log.warn("Could not close input stream", e);
            }
        }
    }

    public static String getMimeType(String extension) throws MimeMappingException {
        try {
            if (mimeMap == null) {
                loadMimeMap();
            }
        } catch (IOException e) {
            throw new MimeMappingException("Could not load mime map", e);
        }
        String mimeType = mimeMap.getProperty(extension);
        if (mimeType == null) {
            throw new MimeMappingException("Could not find mime type");
        }
        return mimeType;
    }

}
